Justification:Acanthurus chirurgus is widely distributed in the Atlantic. It is common and abundant throughout its range. It is harvested in subsistence fisheries and is a targeted food fish in parts of its distribution. There are localized declines in areas where this species is heavily fished (Jamaica), however, there is no indication of global population declines. It is found in a number of marine protected areas in parts of its range. It is therefore listed as Least Concern.

Acanthurus chirurgus is found from South Carolina, USA (juveniles are found to Massachusetts, it is rare north of Florida), Bermuda, and the northern Gulf of Mexico to São Paulo, Brazil. It also occurs on the tropical and subtropical coast of West Africa. Records from West Africa are probably misidentifications of A. monroviae (L. Rocha pers. comm. 2010).

Acanthurus chirurgus is the most abundant surgeonfish in the western Atlantic (L. Rocha pers. comm. 2010). Densities were recorded at 0.05 ind m-2 from Abrolhos Bank, eastern Brazil. It showed higher densities within the no-take area of Timbebas (Francino-Filho et al. 2009). This species had greater abundances in unfished areas than fished areas in Saba Marine Park (Netherlands Antilles) and in Hol Chan Marine Reserve, Belize (Polunin and Roberts 1993). There were order of magnitude differences in biomass among six Caribbean islands studied on which fishing pressure ranged from non existent in Bonaire, increasing through Saba, Puerto Rico, St. Lucia and Dominica and reaching very high intensities in Jamaica, with biomass declining as fishing intensity increased (Hawkins and Roberts 2004).

Acanthurus chirurgus inhabits coral reefs and inshore rocky areas with sand and deep sponge bottoms from 2-70 m. Juveniles use seagrass beds and mangroves as nurseries. It grazes on many species of benthic algae, occasionally on seagrass. It also feeds on the film of algae on the surface of sand undisturbed by surge. Contents of digestive tract includes from 25 to 75% inorganic material, including sand and gravel to 5 mm diameter, Halimeda fragments and sponge spicules. In Abrolhos Bank eastern Brazil, it was recorded to have foraged more frequently over sand bottoms (Francino-Filho et al. 2009).

Pelagic larval stage duration range from 45 to 71 days (M. Bergenius in Rocha et al. 2002), it then settles on reefs when 26.9 mm (Robertson 1992). In Bermuda, juveniles settle onto lagoonal reefs and migrate to the outer reefs as adults (Mutz 2006). The sexes are separate among the acanthurids and there is no evidence of sexual dimorphism. First maturity is at about 17 cm (FL) (Reeson, 1983).

Growth

A. chirurgus displays the highly characterized pattern of asymptotic growth. Terminal size was reached at around age four, and most of the growth occurred within the first 10% of the lifespan, and approximately 85% of somatic size was attained within the first year. The mean maximum age fluctuated from 7 years in Belize to 16 years in Bermuda with a maximum longevity of 30 years in Bermuda (Mutz 2006). Maximum age recorded from San Blas was 13 years (Choat and Robertson 2002). This species has high turnover rates (J.H. Choat pers. comm. 2010).

There are strongly contrasting patterns of habitat variation in demography at five sites studied by Robertson et al. (2005a): In most locations fish settle inshore, grow to about asymptotic size and then, when two to six years old, relocate permanently to outer reefs, where they can reach 30 years. At Venezuela, fish grow very rapidly and do not show asymptotic growth but have shorter life spans of 16 years.

Cleaning Behaviour

At Fernando de Noronha Archipelago in southwestern Atlantic, juveniles hold cleaning stations together with the Blue Tang (Acanthurus coeruleus) and Sergeant Major (Abudefduf saxatilis) and graze algae as well as pick molted skin and parasites from Green Turtles (Chelonia mydas). This behaviour is preceded by a characteristic inspection usually followed by feeding nips on the turtles' skin (head, limbs, and tail), as well as on the carapace. The most inspected and cleaned body parts are the flippers (Sazima et al. 2004).

Acanthurus chirurgus is a component of subsistence fisheries and is caught in traps and gill nets, occasionally by spearing. It is a targeted food fish in Haiti and Jamaica. It is caught incidentally in trap fisheries elsewhere (L. Rocha pers. comm. 2010). It is also a component of the aquarium trade (Global Marine Aquarium Database accessed 21 April 2010). It sells for $29.99-$69.95 online (L. Rocha pers. comm. 2010).

Acanthurus chirurgus is heavily fished in parts of its range (Haiti and Jamaica).

Surgeonfishes show varying degrees of habitat preference and utilization of coral reef habitats, with some species spending the majority of their life stages on coral reef while others primarily utilize seagrass beds, mangroves, algal beds, and /or rocky reefs. The majority of surgeonfishes are exclusively found on coral reef habitat, and of these, approximately 80% are experiencing a greater than 30% loss of coral reef area and degradation of coral reef habitat quality across their distributions. However, more research is needed to understand the long-term effects of coral reef habitat loss and degradation on these species' populations. Widespread coral reef loss and declining habitat conditions are particularly worrying for species that recruit into areas with live coral cover, especially as studies have shown that protection of pristine habitats facilitate the persistence of adult populations in species that have spatially separated adult and juvenile habitats (Comeros-Raynal et al. 2012).

In-Place Research, Monitoring and PlanningIn-Place Land/Water Protection and Management Conservation sites identified:Yes, over part of range Occur in at least one PA:YesIn-Place Species ManagementIn-Place Education